This application claims priority to Japanese Patent Application 2009-156376 filed in Japan on Jun. 30, 2009, the entire disclosure of which is hereby incorporated by reference.
The exemplary embodiments relate to an electrical junction box to be mounted on a motor vehicle or the like and more particularly relates to an electrical junction box provided with a plurality of electrical component mounting sections that are open in a top surface.
Heretofore, an electrical junction box has been installed in an engine room or the like of a motor vehicle in order to enhance efficiency in electrical wiring. This electrical junction box mounts current-carrying components such as lead wires, bus bars, or current-carrying boards, and various kinds of electrical components such as relays, fuses, control devices, connectors for connecting external current-carrying circuits to internal current-carrying circuits, as required.
In the case where exchangeable electrical components such as relays and fuses are mounted on the electrical junction box, it is necessary to easily attach and detach only the electrical components to and from the electrical junction box installed in the motor vehicle. Accordingly, the electrical junction box is provided with electrical component mounting sections that are open in an upper surface of the box. For example, JP 2003-348733 A has disclosed such electrical junction box.
If the electrical component mounting sections are open in the upper surface of the electrical junction box installed in the engine room or the like, there is a possibility that water is accumulated on the upper surface of the electrical junction box and the water enters the box through openings in the sections. If the water contacts with internal electrical components, a problem of electrical leakage or short circuit may be caused.
JP 2002-152943 A has disclosed an electrical junction box in which a special water cut-off wall is provided around the electrical component mounting sections and a special drainage path is provided to extend outward. Republication WO 2006/109804 A has disclosed an electrical junction box in which a special drainage groove is provided in an upper surface of the box.
However, the above electrical junction boxes require an additional space for providing a drainage groove except a space for providing the electrical component mounting sections. This will cause a problem of upsizing the electrical junction box.
Particularly, in the case where the electrical junction box is provided on an upper surface with many electrical component mounting sections, it will be more difficult to obtain a space for providing the drainage groove and an additional problem of heat generation due to many electrical components will be caused.